With a search in the 'MSSQL\Install' directory, you can find both 'create procedures' in 2 different .sql files.
The .get_perf_counters sp collects data from sysalerts and joins it with sysperfinfo.
I noticed that by default you already get a bunch of those alerts (see SQL EM), you can also create them in EM or in perf/sysmon.
The 'sp.._refresh_job' runs probably becuase you installed with the 'replication' option.
I assume you can just delete them from SQL EM
Mario